You only receive a lawyer when you are being charged with a crime. You don't get them for custody battles. If you are a minor and the court feels your best interests are not being represented they may appoint a guardian ad litem over you to make sure your concerns are heard, but you won't be given a lawyer for a custody battle.
The policy limit is the max payable by the insurance company. They can not pay anymore than that.
However, if the at fault person does not have enough limits to cover your injury, you then contact your insurance company and file a claim under your Under-Insured Motorist Coverage.
Since the at fault person has $25K limits, your bills are already at $16K and you are still treating, I suggest you go ahead and call in a claim to your automobile insurance company and have a claim set up under your policies Under-Insured Motorist coverage. (I am assuming you have UIM coverage). That way, your insurance company can go ahead and do their investigation and get their claim ready to step in should it be needed. If it turns out you don't need to make a claim under the UIM coverage on your policy, you can then call your company and let them know so they can close the claim file.